The inventive concept relates to a semiconductor device. More particularly, the inventive concept relates to a semiconductor device having a line pattern and contact plugs formed thereon.
Semiconductor devices are increasingly becoming more and more integrated, i.e., the design rules of semiconductor devices is decreasing. Therefore, the manufacturing of such semiconductor devices must ensure a sufficiently large process margin. For example, the design rules have evolved to be equal to or less than 40 nm. However, a single photo/etch patterning method, which is the technique typically used to form various patterns of semiconductor devices, does not ensure a sufficiently great process margin in the case of a pattern having a line width equal to or less than 40 nm. In particular, the conventional photolithography process of the method has limits with respect to the fineness of the pattern which it can be used to form.
However, recently, a double patterning technique employing a sidewall spacer has made it is possible to form a pattern, in particular, a line/space wiring pattern, having a line width equal to or less than 40 nm. In a device whose line pattern has a line width equal to or less than 40 nm, the diameter (critical dimension) of the contact holes must also be equal to or less than 40 nm. However, neither a single photo/etch patterning technique nor the double patterning technique can be adopted to form a contact hole having a diameter equal to or less than 40 nm. Rather, such a contact hole can only be formed via high-performance photolithography. Even so, a sufficiently large process margin can not be ensured.